Department of Surgery, Radboud University Medical Center Nijmegen, The Netherlands. b.wiering@chir.umcn.nl
Dec, 2005
Fluor-18-deoxyglucose-positron emission tomography (FDG-PET) has emerged as a promising diagnostic modality in recurrent colorectal carcinoma. Whole-body FDG-PET may be an accurate diagnostic modality to determine whether patients with recurrent hepatic disease are suitable candidates for curative resection. Reports on the use of FDG-PET in patients with recurrent colorectal carcinoma are scarce, especially those on colorectal liver metastases. To assess the usefulness of this emerging modality for the selection of patients to undergo resection for colorectal liver metastases, a systematic (meta)-analysis of the current literature was conducted. In the absence of randomized controlled clinical trials, a traditional meta-analysis could not be performed. An alternative strategy was designed to evaluate the current literature. After a literature search, an index score was devised to evaluate the articles with regard to the impact of FDG-PET in patients with colorectal liver metastases. The index scored articles on several items and, as such, could be considered an objective approach for the assessment of diagnostic, nonrandomized clinical trials. The proposed index proved to be an independent instrument for judging several research questions and was used systematically to address the sensitivity, specificity, and clinical impact of FDG-PET in patients with colorectal liver metastases. For FDG-PET, the pooled sensitivity and specificity results were 88.0\% and 96.1\%, respectively, for hepatic disease and 91.5\% and 95.4\%, respectively, for extrahepatic disease. For the 6 articles that reported the highest scores on the index, the sensitivity and specificity of FDG-PET for hepatic metastatic disease were 79.9\% and 92.3\%, respectively, and 91.2\% and 98.4\%, respectively, for extrahepatic disease, respectively. For computed tomography, the pooled sensitivity and specificity results were 82.7\% and 84.1\%, respectively, for hepatic lesions and 60.9\% and 91.1\%, respectively, for extrahepatic lesions. The percentage change in clinical management due to FDG-PET was 31.6\% (range, 20.0-58.0\%) in the articles that scored above the mean and reported this item. For the 6 highest scoring studies, the percentage change in clinical management was 25.0\% (range, 20.0-32.0\%). Despite apparent omissions in the literature, the combined sensitivity and specificity of FDG-PET clearly indicated that FDG-PET has added value in the diagnostic workup of patients with colorectal liver metastases. FDG-PET can be considered a useful tool in preoperative staging and produced superior results compared with conventional diagnostic modalities, especially for excluding or detecting extrahepatic disease.